Computer and communication technologies continue to advance at a rapid pace. Indeed, computer and communication technologies are involved in many aspects of a person's day. For example, many devices being used today have a small computer inside of the device. These small computers come in varying sizes and degrees of sophistication. Computers commonly used include everything from hand-held computing devices to large multi-processor computer systems.
Computers are used in almost all aspects of business, industry and academic endeavors. More and more homes are using computers as well. The pervasiveness of computers has been accelerated by the increased use of computer networks, including the Internet. Most companies have one or more computer networks and also make extensive use of the Internet. The productivity of employees often requires human and computer interaction. Improvements in computers and software have been a force for bringing about great increases in business and industrial productivity.
A computer network may be organized as a stack of layers. The purpose of each layer is to offer certain services to the higher layers. Typically, layer N on one computing device communicates with layer N on another computing device. The rules and conventions used in this communication are collectively known as the layer N protocol. Of course, in reality no data are directly transferred from layer N on one machine to layer N on another machine. Instead, each layer passes data and control information to the layer immediately below it, until the lowest layer is reached. The lowest layer generally includes the physical medium through which the data is actually transferred.
One popular model for computer networks is the Open Systems Interconnection (OSI) model. The OSI model includes seven layers. In ascending order, these layers include the physical layer, the data link layer, the network layer, the transport layer, the session layer, the presentation layer, and the application layer. In many computer networks, the protocols used to determine who goes next on a multiaccess channel belong to a sublayer of the data link layer called the Medium Access Control (MAC) sublayer. The MAC sublayer is important in many local area networks (LANs), many of which use a multiaccess channel as the basis for communication.
A wireless LAN is a system in which every device (often called a wireless station) has a radio modem and an antenna with which it can communicate with other devices and/or systems. Wireless LANs are becoming increasingly common in homes, office buildings, public places such as airports and coffee shops, and other places. There is a standard for wireless LANs, called IEEE 802.11, which many systems implement and which is becoming very widespread. Benefits may be realized by improved systems and methods that facilitate wireless networking of electronic devices in a more efficient and cost-effective manner.